CloudOn, a free iPad app that offered Microsoft Office functionality with Dropbox support, appeared briefly in the App Store yesterday before going up in a puff of smoke a short time later.

CloudOn has responded saying their app has "sold out", but we think this may have had something to do with server overload.

Thanks for your support of CloudOn! We're currently sold out. We look forward to the feedback we will receive as we continue to support the many users that have registered in this first phase.

The fact that CloudOn came with full Dropbox support for storing and managing office files on-the-go was a great idea for power users, and the overall offering is unique in respect to beating Microsoft to the punch at their own game. This could be another reason the app is no longer available, as Microsoft could have called shenanigans if CloudOn didn't go through the appropriate channels before release.

I gave it a quick whirl when it was actually up and running, and noticed the app was somewhat sluggish from the get-go (probably due to how much it relies on the cloud backend to get things done paired with the influx of users hammering their servers).

We'll let you know as soon as CloudOn is back in the App Store. In the meantime, here's its description:

Use Microsoft Word, Excel and PowerPoint on your iPad to create or edit documents.